INTRAOCULAR LENS WITH IMPROVED HAPTIC LOCKING

Abstract: An intraocular lens (10) includes an optic body (12), and a pair of diametrically oppositely disposed elongate support haptics (14) extending radially outwardly and circumferentially on the optic body (12) to define a distal end foot portion (22) supportingly engageable with eye tissue and terminating in a distal (24) end for the haptic. In a first position for the haptics, the distal end foot portions (22) are spaced from the optic body (12). One of the optic body (12) and support haptic (14) defines releasable constraining features for engaging one of the optic body (12) or the other of the pair of haptics (14) to constrain the haptic (14) in a second position in which the distal end foot portion (22) thereof is adjacent to the optic body (12). In the second configuration of the intraocular lens (10) it is possible to pass the lens (10) into an eye via a surgical incision only slightly larger than the size of the optic body.

Description: INTRAOCULAR LENS WITH IMPROVED HAPTIC LOCKING Background of the Invention Field of the Invention The present invention is in the field of intraocular lenses. More particularly, the present invention relates to intraocular lenses having elongate cantilevered haptic portions which at one proximal end thereof secure to an optic body of the lens, and at a distal end thereof are free. A distal end portion of the haptics define a foot portion whereat the haptic engages surrounding eye tissues to support and center the lens optic body in the eye. To facilitate insertion of the intraocular lens into the anterior or posterior chamber of the eye via a surgical incision which is as small as practicable, the lens includes provisions to retain or lock the haptics at or adjacent their free distal ends into a constrained position in which the haptics are disposed more closely to the optic body. Related Technology Intraocular lenses are implanted in human eyes following removal of the natural lens because of injury, or more freguently, because of cataract. During such a surgical procedure, the natural lens capsular hexis is incised, and the natural lens material is removed. Freguently, this natural lens removal is achieved with a phfacoemulsifier accompanied with irrigation and suction of the emulsified lens particles. Currently, a surgical technigue which reduces trauma and speeds recovery time for the patient is favored. This technigue also allows sutureless or single-stitch closure of the principal surgical incision site. With this technigue a tunnel type of incision is employed starting from the sclera of the eye outwardly of the cornea and extending inwardly and forwardly into the anterior chamber of the eye forward of the iris. The natural lens is removed, leaving the capsular bag intact. Subsequently, the intraocular lens is reduced in size 5 by constraining the support structures, or haptics, of the lens. The intraocular lens as so constrained is passed through the surgical tunnel incision inwardly and forwardly toward the inner surface of the cornea, and then is tipped inwardly to pass through the dilated iris and 10 into the capsular bag. This procedure involves the sequential release of the constrained lens so that a leading one of the haptics extends through the pupil of the iris and into the capsular bag. This leading haptic is followed by the optic body of the intraocular lens, and 15 the lens is rotated slightly to enter the trailing haptic into the capsular bag. Desirably, the intraocular lens provides an effective optical diameter which is as large as is practicable while retaining a diameter for the optic body which is still 20 small enough to allow passage of the lens through a small incision. By way of example, the effective diameter of the lens support structure in the capsular bag may be from 10 to about 14 mm in order to supportingly engage the surrounding eye tissues. The lens may have to pass 25. through a dilated iris with a diameter of about 6 to 7 mm. Consequently, the optic body diameter of the lens may ' be limited to a diameter of about 5.5 or 6 mm, and the lens will be passed through a surgical tunnel made with an incision tool having a width equal to or just slightly 30 wider than the diameter of the optic body of the lens. A conventional intraocular lens is known in accord with United States patent 4,615,701, issued 7 October 1986, to R. L. Woods. This patent to Woods is believed to teach a variety of intraocular lens designs which include 35 various schemes for temporarily retaining or locking the free ends of the filamentary cantilevered haptics in a constrained position at a peripheral edge of the optic body of the lens. Generally, these lens designs include plural axially extending holes which allow the implanting physician after inserting the lens through an incision into the anterior chamber of the eye, to maneuver the lens through the iris into the ciliary sulcus, or more particularly, within the capsular bag, by use of a hooked manipulation tool. According to at least one version of the Woods lens, the free ends of the haptics include axially extending end portions which hook into the axially extending holes at a peripheral portion of the lens optic body to temporarily constrain the haptics while the lens is inserted through the incision into the eye. Subsequently, the haptic distal ends are unhooked from the holes to allow the haptics to extend outwardly into supporting engagement with the surrounding eye tissues. Unfortunately, such axially extending maneuvering holes present an optical difficulty for an intraocular lens. This difficulty involves the refraction of light from the holes and the creation of objectionable glares, stars, or sunbursts, depending on the particulars of the lighting conditions, and the perceptions of the patient. Consequently, such lenses generally include a central portion of the optic body which is considered the optically active part of this body, and a peripheral portion integral with the optic body which is for physical attachment of the haptics, for the maneuvering holes, and for haptic constraint features. Of course, this provision of a central optic portion and a surrounding peripheral portion of the optic body means that in order to provide an optic of a certain size, the lens must be larger by at least the size of the peripheral portion. This increase in lens size above the active optic portion of the optic body is a great disadvantage because surgeons desire to keep the size of the surgical incision as small as possible. Additionally, the axially extending distal end portions of the haptics can irritate delicate eye tissues. This aspect is especially a concern with the tunnel-type of sutureless or single-stitch type of incision for lens insertion. With this type of incision the tunnel extends from the sclera somewhat upwardly toward the inner surface of the cornea. As the intraocular lens clears the inner extent of this surgical tunnel, the physician tips it downwardly to pass through the iris and into the capsular bag. Under these circumstances, the physician must be careful not to abrade or otherwise injure the inner surface of the cornea. Were a haptic to come loose at this time its distal end could damage the cornea inner surface. For this reason, reliable securement of the haptics is especially important. Also, in the event that securement of the haptics is lost at this moment in the procedure, preferably the haptics have a configuration of their distal end portions which inflicts only minimal or no trauma on the inner surface of the cornea. Considering the version of the Woods lens which uses axially extending distal end hooks to secure the haptic distal end portions posteriorly of the lens, it is easily seen that if one of these haptics gets free at the wrong moment, the distal end hook of the haptic could badly gouge the inner corneal surface. Other versions of the intraocular lens taught ' by Woods include various holes, recesses, or cavities extending generally in the plane of the lens optic at a peripheral portion thereof and opening radially outwardly. The free distal ends of the haptics include various hook, or enlargement shapes for the distal end portions of the haptics in order to releasably engage into the holes, recesses, or cavities of the peripheral portions of the optic bodies. These in-plane haptic engagement features present much the same disadvantages as the axially extending maneuvering holes in that they present refractive discontinuities in the material of the optic body which can cause the same sort of objectionable visual aberrations mentioned above. Further to the above, the axially extending maneuvering holes of conventional intraocular lenses, as well as the peripheral haptic constraint features, such as holes, recesses, and cavities, taught by the Woods patent have a certain degree of undesirability because these features provide a possible sheltered and inaccessible harbor for bacteria, and for other contaminants in the surgical environment. While intraocular lenses having such holes and recess have been used successfully for years, a desirable objective in the art is to eliminate as much as is practicable such harbors for bacterial growth which also can capture and hold foreign contaminants. Summary of the Invention In view of the deficiencies of the pertinent art, there is a need for an improved intraocular lens which includes features for temporarily constraining cantilevered haptic portions of the lens while the latter is inserted through an incision into an eye. The haptics should be constrained temporarily and without damage in a position adjacent to the optic body of the lens to ease insertion of the lens through the surgical incision. , However, the constrain features should be easily and controllably disengageable once the lens is within the eye, while avoiding unintended disengagement while the lens is being inserted through the surgical incision. Additionally, the haptic constraint features should avoid as much as is possible the creation of refractive discontinuities of the optic body of the lens. Still further, the constraint features for the haptics should not create distal end portion features on the haptics which can dig into and irritate delicate eye tissues when the haptics are in their extended supporting positions within the eye. Thus, a primary object for the present invention is to provide an intraocular lens which substantially satisfies the above desirable goals for such a lens. More particularly, an objective for the present 5 invention is to provide an intraocular lens which includes an optic body and a support haptic at a proximal portion securing to the optic body and extending outwardly and circumferentially to supportingly engage eye tissue. The intraocular lens includes temporary constraint features 10 for the haptic so that a distal free end of the haptic is disposed adjacent to a peripheral edge of the optic body while the lens is inserted through a surgical incision. This lens also includes either or both of a peripheral portion of the lens optic body which is circumferentially 15 continuous and free of haptic constraint features possibly producing undesirable optical aberrations, or a haptic distal end portion which is free or substantially free of haptic constraint features potentially damaging or irritating to eye tissues. 20 According to one particular embodiment of the present invention, the lens optic body is fully optically active, without a peripheral portion compromised in its optical performance by the presence of any holes, cavities, recesses, or other such features which could interfere 25. with the optical performance of the optic body. A pair of haptics secure to the optic body at diametrically opposite locations and extend outwardly and circumferentially to distal ends thereof. Each of the haptics adjacent its distal end defines a distal end portion with a small 30 aperture therein. In order to constrain these haptics for insertion of the lens through a surgical incision, the distal ends of the haptics are connected together by a loop of suture material, and are drawn together close to the periphery of the optic body. After the lens is within 35 the eye, the loop of suture material is clipped and removed. The haptics then return toward their unconstrained positions to supportingly engage surrounding eye tissue. Importantly, the securement of the haptics is very reliable, and the distal ends of the haptics are free of features potentially damaging to eye tissues should the haptics get free inadvertently. Also, the full diameter of the optic body is optically active without compromising features. Alternative embodiments of the present invention offer similar combinations of features which allow a physician to choose the combination of features best matching their surgical skills and technique, and the needs of particular patients. For example, one version of the present lens uses distal end portions of the haptics which are formed into almost completely closed shepherd's hooks. These hooks may be engaged very securely with one another in order to constrain the haptics for insertion of the lens through a surgical tunnel. On the other hand, should the haptics inadvertently get free, the shepherd's hook configuration of the haptic distal ends presents a rounded configuration with virtually no free haptic end which could gouge delicate eye tissues. That is, the end of the haptic is shielded from gouging into eye tissues by a closely adjacent medial shaft portion of the haptic. Other versions of the present inventive intraocular lens present a radial boss outwardly of the optic body so that the full diameter of the optic body is optically active without compromising features. This boss defines an axially open generally circumferential groove into which a medial shaft portion of the opposite haptic is receivable to constrain the haptic for surgical insertion into an eye. The circumferential groove is not nearly so likely to catch bacteria or foreign matter contamination as is the peripheral edge features of conventional lenses. According to one embodiment of the present lens, the boss is defined by a portion of the haptics themselves which portion provides a transition to the optic body. Other versions of the present lens provide a bite between the haptic and optic body which closes as the haptics are moved toward their constrained positions. The distal end portions of the haptics are configured to capture in these bites, so that the haptics mutually constrain one another. Yet another lens version uses a shallow groove formed by a bore nearly tangential to the lens optic body and extending therein as a complete bore only a short distance. A distal end of a haptic is captured in this shallow groove and bore. The shallowness of the groove and bore avoids significant compromise of the optical function of the optic body, and also avoids harboring bacteria and other contamination at the surgical site. The above, and additional objects and advantages of the present invention will appear from a reading of the following detailed description of particularly preferred exemplary embodiments of the invention, taken in conjunction with the appended drawing Figures, rendered at differing scales in the various Figures to better depict salient features of the embodiments, and in which: Description of the Drawing Figures Figures 1A and IB provide respective plan and side elevation views of an intraocular lens embodying the present invention; Figure 2 provides a plan view of the lens of Figures 1 in a condition with haptic portions thereof constrained preparatory to surgical implantation of the intraocular lens; Figures 3 and 4 provide respective plan views of an alternative embodiment of intraocular lens according to the present invention in unconstrained and constrained conditions, respectively; Figures 5 and 6 show respective plan views of yet another alternative embodiment of intraocular lens according to the present invention in unconstrained and constrained conditions, respectively; Figure 5A is a fragmentary cross sectional view taken along line A-A of Figure 5; Figures 7 and 8 provide respective plan views of still another alternative embodiment of intraocular lens according to the present invention in unconstrained and constrained conditions, respectively; Figure 7A is a fragmentary cross sectional view taken along line A-A of Figure 7; Figures 9 and 10 are respective plan views of an additional alternative embodiment of intraocular lens according to the present invention in unconstrained and constrained conditions, respectively; Figures 11 and 12 show yet another alternative embodiment of the present intraocular lens in unconstrained and constrained positions, respectively; Figures 13 and 14 provide plan views of yet another alternative embodiment of intraocular lens embodying the present invention in respective unconstrained and constrained positions; Figure 13A is an enlarged fragmentary view of a portion of Figure 13; and Figures 15 and 16 likewise provide plan views of still another alternative embodiment of intraocular lens embodying the present invention, and in respective unconstrained and constrained conditions; Description of the Preferred Exemplary Embodiments It should be noted first of all that the various views of the drawing Figures are rendered at differing scales in order to better depict salient features of the invention. Viewing Figures 1A and IB, an intraocular lens 10 is seen in respective plan and elevation view. The plan view of Figure 1A provides a view along the optic axis which the lens 10 will have when implanted in an eye. The lens 10 includes a transparent optic body 12 of bi-convex configuration, and of selected dioptic strength to correct the vision of a patient whose natural lens has been removed, as is well understood. The optic body portion 12 need not be of bi-convex configuration, but may equally be of plano-convex, concavo-convex, or of other configuration without departure from the present invention. Importantly, the optic body has an optically active zone, indicated with the numeral 12a, which encompasses the entire diameter of the optic body in the embodiment shown in Figures 1. As those skilled in the pertinent arts will recognize, the optic body 12 is free of a conventional circumferential peripheral portion of the optic body, which portion is at least compromised (or perhaps is ineffective) optically because of, for example, axially extending maneuvering holes, vent holes, or various peripheral haptic constraint features defined in this peripheral portion of the optic body. Securing to the optic body and extending outwardly and circumferentially thereof from diametrically opposite locations is a pair of support haptic members 14. Preferably, the haptics 14 may be integral with the optic body 12. For example, the entire lens 10 may be formed of a single piece of polymer material having acceptable optical and physical properties. Examples of such materials are polymethylmethacralate (PMMA) , and polypropylene. However, these haptics 14 may also be joined to the optic body by thermal stake welding, adhesive or solvent bonding, ultrasonic welding, or other joining methods without departure from the present invention. In this latter case, the optic body 12 may be made of a material such as PMMA which has outstanding optical properties and organic inertness, and the haptics may be made of a more flexible material such as polypropylene, which is also acceptably benign biologically. The haptics 14 include a proximal transition portion 16 joining with the optic body 12, and a proximal curve section 18 leading to a medial shaft section 20. The medial shaft section leads to a distal end foot portion 22, which terminates at a distal end 24. Those ordinarily skilled in the pertinent arts will appreciate • that the haptic 14 is an elongate, somewhat filamentary structure, which at its foot portion 22 supportingly engages and is pressed inwardly slightly toward the optic body by surrounding eye tissues when the lens 10 is in an eye. That is, when the lens 10 is implanted in an eye, the haptics 14 do not occupy their unconstrained positions as illustrated in Figure 1A, but are compressed inwardly radially toward the optic body 12. Thus, the haptics 14 provide support and centration for the optic body 12 within the eye. Figure 1A also illustrates that the haptics 14 at the distal foot portions 22 immediately adjacent to the distal ends 24 each define an aperture 26. Figures 1A and IB in conjunction depict that the optic body 12 includes a peripheral surface 28 which is circumferentially continuous, except for the transition portions 16 which lead outwardly from the body 12 to the remainder of the haptics 14. That is, the peripheral surface 28 is not interrupted by holes, recesses, cavities or other conventional features which are employed to constrain the haptics in preparation for insertion of the lens 10 through a surgical incision and into the capsular bag of an eye. Moreover, the entire optic body 12 of the lens 10 is of uniform optical integrity, and is without axially extending maneuvering holes which 'are conventionally used to move the lens 10 during a surgical procedure. Consequently, it is to be understood that the optic body 12 defines an optically active and optically integral zone 12a which encompasses the entire diameter of this optic body. Accordingly, it is seen that the zone 12a of optical integrity for the optic body 12, and the diameter of this body are one and the same. As a result, the lens 10 provides the largest possible optic diameter for a given size of lens which must be inserted through a surgical incision. It follows that the surgical incision which must be made in the eye in order to insert the lens 10 is as small as practicable for each particular optical diameter of lens required for various patients. Figure 2 depicts that in preparation for surgical implantation of the lens 10, the haptics 14 are connected to one another by a loop 30 of suture thread. This loop 30 is drawn taught to pull the haptics 14 at their distal end foot portions 22 adjacent to the peripheral edge surface 28 of the optic body 12. As so constrained, the lens 10 may be advanced through a surgical incision, and particularly through a tunnel-type of sutureless or single-stitch incision, and into the capsular bag of an eye. The loop 30 of suture material provides very secure constraint of the haptics 14, with virtually no risk that the haptics will inadvertently become freed and damage eye tissues as they return toward their unconstrained positions seen in Figure 1A. On the other hand, the constrained lens of Figure 2 defines a diameter essentially the same as the diameter of optical zone 12a. This is the size of diameter which must be passed through the surgical incision and into the capsular bag of the eye. Consequently, the required incision need be no bigger than that required to pass the effective optical diameter 12a of the optic body 12. In other words, the lens 10 does not include the conventional peripheral portion which is of compromised optical performance for the patient. Additionally, it follows that for a certain size of surgical incision, the lens 10 provides a larger centration error margin for positioning of the optic body 12. So long as the optic body 12 is within this centration error margin, the patients vision will not be compromised because the entire diameter of the optic body 12 has optical integrity not compromised by peripheral features. After the lens 10 is inserted into the capsular bag of the eye, the loop 30 may be clipped to allow a leading one of the haptics to extend toward its unconstrained position through the dilated iris. Subsequently, the lens is rotated into position with the trailing haptic following the lens into the posterior chamber of the capsular bag. Figures 3 and 4 depict another alternative embodiment of the present inventive intraocular lens. In order to obtain reference numerals for use in describing the embodiment of Figures 3 and 4, features which are analogous in structure or function to those described above are referenced with the same numeral used above, but having a prime added thereto. Viewing Figure 3, it is seen that the intraocular lens 10' includes an optic body 12' having a fully effective optic diameter 12a'. A pair of haptics 14' extend outwardly and circumferentially from proximal transition portions 16' which are disposed diametrically opposite to one another. The haptics 14' include proximal curve sections 18', medial shaft sections 20', and distal end foot portions 22' terminating at respective distal ends 24'. Lens 10' also includes a circumferential peripheral edge surface 28', which is continuous without interruption by holes, cavities, recesses or other features with exception of the transition portions 16', which are outside of the optical diameter 12a'. However, the embodiment of Figures 3 and 4 does not include a distal end portion aperture 26 like the embodiment described above. Instead, the haptics 14' each include a respective shepherd's crook feature, which is generally referenced with the numeral 32. This shepherd's crook feature is formed by a portion 34 of the distal end portion 22' of the haptic which curls around inwardly toward the optic body 12 almost to the extent of having a free end 36 thereof contact the distal end portion 22'. Accordingly, in Figure 3 a dashed line 38 schematically depicts the ark of the surrounding eye tissues of the capsular bag. As can easily be seen 1 , when the haptics 14' are in the eye and supportingly engaging eye tissues, the shepherd's crook feature 32 presents only rounded and nonirritating surfaces to the eye tissues. However, in order to temporarily constrain the haptics 14' for insertion of the lens 10' through a surgical incision and into the eye, the shepherd's crook features 32 are engaged with one another to dispose the haptic distal end portions 22' adjacent the optic body 12'. In this case, the distal end portions 22' of the haptics 14' actually cross over or under the optic body 12' to engage one another. As can be seen from Figure 4, the lens 10' in its constrained haptic condition may pass through a tunnel incision which is only wide enough to pass the optic diameter 12a' of the optic body 12'. That is, this embodiment of the inventive intraocular lens also has no peripheral rim portion which is of compromised optical quality. After the lens 10' is passed through the surgical incision and into the anterior chamber of the eye, it is tipped edge-on toward the dilated iris, and the haptics 14' are unhooked from one another to allow the leading one of the haptics to extend into the capsular bag. The trailing haptic is constrained by a surgical tool, usually by a pair of forceps, and is released after or as the optic body follows the leading haptic into the posterior chamber. As before, a slight rotation of the lens 10' will ordinarily be sufficient to cause the trailing haptic to follow the lens optic 12 into the posterior chamber and to seat this haptic in the capsular bag. Another embodiment of the present inventive intraocular lens is depicted in Figures 5, 5A, and 6. Again, reference numerals introduced above are used to reference features which are analogous in structure and function. Because the reader will by now be familiar with the essential elements of the intraocular lens of the present invention, the use of primes on reference is not hereafter continued except as noted. Viewing Figures 5, and 5A, an intraocular lens 10 includes an optic body 12 having a fully effective optic diameter 12a. A pair of haptics 14 extend outwardly and circumferentially from proximal transition portions 16 which are disposed diametrically opposite to one another. The haptics 14 include proximal curve sections 18, medial shaft sections 20, and distal end foot portions 22 terminating at respective distal ends 24. Lens 10 also includes a circumferential peripheral edge surface 28, which is continuous without interruption by holes, cavities, recesses or other features with exception of the transition portions 16, and two other features yet to be explained, but all of which are outside of the optical diameter 12a. The distal end portions 22 include a rounded bulbular end portion 40 which is advantageously gentle to contacted eye tissues. Figures 5, and 5A illustrate that the lens 10 includes a pair of bosses, each referenced with the numeral 42, and each extending radially outwardly and circumferentially outside of the edge surface 28. That is, the bosses 42 lie outside of the diameter 12a of the optic body, and preferably are integral therewith. Each boss 42 defines an arcuate and axially opening groove 44, which is best seen in Figure 5A. Preferably, the grooves 44 open posteriorly. Viewing Figure 5A, it is seen that the bosses 42 define a radially outer and axially extending wall portion 46, which radially outwardly bounds the groove 44. As Figure 6 illustrates, in order to constrain the haptics for insertion of the lens through a surgical incision and into an eye, the haptics are temporarily forced radially inwardly at their distal end foot portions 22, so that these portions are received into the grooves and engage the wall portions 46. The dashed line outline of Figure 5A shows the cross section of the haptic 14 as it appears when the haptic is captured and constrained in the groove 44 of boss 42. In its constrained-haptic condition, the lens 10 seen in Figure 6 is only slightly larger in diameter than the diameter 12a of the optic body 12, which is the same as the effective optical diameter of the optic body 12. Because the radial dimension of the haptics 14 is small in comparison to the diameter of the optic body 12, the lens 10 can be passed through a surgical incision which is only very slightly larger than the diameter 12a of the optical body 12. After the lens 10 of Figures 5, 5A, and 6 is inserted into the anterior chamber of an eye, the haptics 14 are released from the bosses 42, and the insertion of the lens into the capsular bag of the eye is completed much as described above. Figures 7, 7A, and 8 depict another alternative embodiment of the present inventive intraocular lens in which the functions of the transitions portions 16 of the lens and of the bosses 42 seen in the embodiment of Figures 5, 5A, and 6 are combined into a single structural feature. Because these structural features combine functions described above, primes are used in referring to these features so that the reader will understand that a functionally equivalent, but not necessarily structurally identical, feature is being referenced. Viewing the lens 10 of Figures 7-8, the transition portions 16' are , provided with a circumferentially extending and axially opening groove 44'. Again, this groove is bounded radially outwardly by a wall portion 46' of the transition portion 16'. As Figure 8 illustrates, in the constrained-haptic condition of the lens 10, the distal foot portions 22 of the haptics 14 are forced radially inwardly and into the grooves 44'. As so captured, the haptics 14 lie immediately outwardly of the peripheral edge surface 28 of the optic body 12. Consequently, the lens 10 of Figures 7-8 can be inserted into an eye through an incision which is only slightly larger than the diameter and effective optical diameter of the optic body 12. Figures 9 and 10 depict an alternative embodiment of the present inventive intraocular lens. Again, reference numerals introduced above are used to refer to features of the lens of these drawing Figures which are analogous in structure or function to those described above. Consequently, it is seen that the lens 10 includes an optic body 12 having a fully effective optic diameter 12a. A pair of haptics 14 extend outwardly and circumferentially from proximal transition portions 16 which are disposed diametrically opposite to one another. The haptics 14 include proximal curve sections 18, medial shaft sections 20, and distal end foot portions 22 terminating at respective distal ends 24. Lens 10 also includes a circumferential peripheral edge surface 28, which is continuous without interruption by holes, cavities, recesses or other features with exception of the transition portions 16, which are outside of the optical diameter 12a. The distal end portions 22 include a rounded bulbular end portion 40 which is advantageously gentle to contacted eye tissues. In the embodiment of the lens 10 seen in Figures 9 and 10, the transition portions 16 and proximal curve sections 18 are swept circumferentially with respect to the optic body 12. That is, these transition and proximal curve features are disposed somewhat tangentially with respect to a tangent at the diameter of peripheral outer surface 28. Consequently, the outer surface 28 in conjunction with the medial section 20 of haptic 14 immediately adjacent to the proximal curve section 18 cooperatively define a bite, which is referenced with the numeral 48. This bite 48 is configured to be slightly larger in radial dimension 50 than the radial thickness 52 of the distal foot portion 22 of the haptics 14. Also, the bulbular distal end portion 40 is sized to be slightly larger than the bite 48. Figure 10 illustrates the constrained-haptic condition for the lens of Figures 9 and 10. In order to place the lens in the condition of Figure 10, the haptics 14 are forced radially inwardly at their distal end foot portions 22. This radially inward movement of the haptics 14 slightly closes the bites 48. Additionally, the distal foot portions 22 are forced slightly out of the plane of the optic body 12 so that the bulbular end portion 40 passes the bite 48 far enough to be received between the surface 28 of the optic body 12 and the medial shaft portion 20 of the other haptic. Once the haptic 14 is in this position, the bulbular end portion 40 is placed axially into and slightly beyond the space between the optic body 12 and the other haptic, and is moved into the bite 48. As Figure 10 illustrates, the haptics at their transition portions 16 and proximal curve sections 18, and in cooperation with the peripheral surface 28 of the optic body 12 defining bites 48, capture each other in the constrained-haptic condition of the lens 10. After the lens 10 of Figures 9 and 10 is inserted into an eye, the haptics 14 are easily released from their condition of Figure 10, and extend toward their condition of Figure 9. Consequently, the haptics 14 of Figures 9 and 10 also present gently rounded surfaces at the bulbular end features 40 to the engaged eye tissue. Figures 11 and 12 depict yet another alternative embodiment of the present inventive intraocular lens. Again, familiar reference numerals are used to reference features analogous in structure or function. Intraocular lens 10 includes an optic body 12 having a fully effective optic diameter 12a. A pair of haptics 14 extend outwardly and circumferentially from proximal transition portions 16 which are disposed diametrically opposite to one another. The haptics 14 include proximal curve sections 18, medial shaft sections 20, and distal end foot portions 22 terminating at respective distal ends 24. Lens 10 also includes a circumferential peripheral edge surface 28, which is continuous without interruption by holes, cavities, recesses or other features with the exception of the transition portions 16, which are outside of the optical diameter 12a. The distal end portions 22 include a rounded bulbular end portion 40 which is advantageously gentle to contacted eye tissues. However, the embodiment of Figures 11 and 12 includes a radially inwardly concave reentrant curve 54 defined by the medial shaft section 20 of the haptics 14. This reentrant curve 54 of the shaft section 20 cooperates with the adjacent proximal curve section 18 to define a cove 56. Immediately adjacent to the cove 56, the medial shaft portion 20 defines a radially inwardly convex curve 58, so that a radially inward projection 60 is defined by the shaft portion 20 distally of the cove 56. Also, in the distal foot portion 22 of the haptics 14, and distally in succession along the length of the haptic, the latter define a radially inwardly concave curve 62, a radially inwardly convex curve 64, and a radially inwardly concave curve 66. The result is that the foot portion 22 includes a radially outwardly disposed recess at 68, and a radially outwardly extending projection 70 disposed immediately distally of the recess 68 and proximally of the bulbular end 40. Viewing Figure 11, it is immediately seen that the haptics 14 present only gently rounded surface features to supporting eye tissues in the foot portions 22. However, as Figure 12 depicts, the lens 10 can be placed in a constrained-haptic condition by forcing the distal foot portions 22 radially inwardly so that the recess 68 is disposed at the reentrant curve 54 of the medial haptic portion adjacent to proximal curve section 18, and at cove 56, and so that the projection 70 is caught behind (axially of) the projection 60. Again, the lens 10 of Figures 11 and 12 may be passed into an eye through an incision which is only slightly larger than the diameter of the optic body 12. Once inside the eye, the haptics 14 are easily released from their constrained condition, and extend toward their unconstrained condition seen in Figure 11. Implantation of the lens 10 of Figures 11 and 12 is completed much as described above. Figures 13, 13A, and 14 depict still another alternative embodiment of the present inventive intraocular lens. In this instance also, familiar reference numerals are used to reference features analogous in structure or function to those depicted and described previously. Intraocular lens 10 includes an optic body 12 having a substantially fully effective optic diameter 12a. A pair of haptics 14 extend outwardly and circumferentially from proximal transition portions 16 which are disposed diametrically opposite to one another. The haptics 14 include proximal curve sections 18, medial shaft sections 20, and distal end foot portions 22 terminating at respective distal ends 24. Lens 10 also includes a circumferential peripheral edge surface 28, which in this instance is interrupted by a pair of shallow circumferentially extending grooves 72. Viewing Figures 13, and 13A, it is seen that the grooves 72 are shallow because they are formed by the transection of surface 28 by a pair of comparatively short blind bores 74 extending along lines 76 which are tangent to a circle 78 at a diameter only slightly less than the diameter 12a of the optic body 12. The diameter of the bores 74 is selected to snugly receive the distal end foot portion 22 of the haptics 14. As is seen in Figure 13, the distal end foot portions 22 of the haptics 14 are essentially of a constant dimension along their length and follow a smooth spiral curve. Consequently, the diameter of circle 78 is selected with a view to the dimension of the distal end portion 22 of the haptics 14 so that a blind end wall 80 of the bore is spaced only slightly from an adjacent end 82 of the groove 72, and the bore 74 defines a short side wall 84. The end 82 of groove 72 is also an end of the side wall 84. The length of side wall 84 is that length of the bores 74 which is completely surrounded by the material of the optic body 12. Outwardly of the end 82 of the wall 84, the bores 74 break through the surface 28, and define the grooves 72 on the surfaces 28. Because the lines 76 are tangent to the circle 78 at a diameter just slightly less than the full diameter of the optic body 12, the latter has an optically effective diameter which is substantially the same as the diameter of the optic body 12 itself. That is, the encroachment of the bores 74 into the optically effective diameter of the optic body 12 is not very much in the radial sense, and is of very limited circumferential extent so that the great majority of the optic body 12 is fully effective optically and is not compromised by the presence of the bores 74. Figure 14 illustrates that the lens 10 of Figures 13 and 14 may be placed into its constrained-haptic condition by forcing the distal end foot portions 22 of the haptics 14 radially inwardly toward the peripheral surface 28, and then axially along the length of the haptic at its distal end foot portion 22 into the respective bores 74. The haptics 14 may have to be sprung slightly radially inwardly at their foot portions to align these portions with the bores 74. As mentioned, the bores 74 are sized to snugly receive the distal end foot portions 22 of the haptics 14. Alternatively, the foot portions may be a snug slip fit into the bores 74, or a slight interference fit may be employed to retain the foot portions 22 in the bores 74. In the former case, the snugness of the fit between the bores 74 and the foot portions 22, along with a possible misalignment of the foot portion with the bores 74 may be effective to bind and retain the foot portions in the bores 74. If a slight interference fit is employed between the foot portions 22 and the bores 74, then these features will be engaged with one another forcefully by the use of forceps or other tools. However, recalling the small scale of the intraocular lens 10 and its haptics 14, as well as the polymeric nature of the materials of construction, it is to be appreciated that the force level necessary to engage the haptic foot portions 22 into the bores 74 will not be very great. After the intraocular lens of Figures 13 and 14 is inserted into an eye, the haptics 14 are released from their constrained conditions by withdrawal of the foot portions 22 from the bores 74. Consequently, the haptics 14 extend toward their unconstrained positions depicted in Figure 13, to supportingly engage surrounding eye tissues. Figures 15 and 16 illustrate another alternative embodiment of the intraocular lens according to the present invention. The lens 10 of Figures 15 and 16 is just like that of Figures 13 and 14, with the exception of features to be described. Consequently, the by-now familiar reference numerals are again used to refer to features which are analogous in structure or function to features described above. The lens 10 of Figures 15 and 16 includes haptics 14 with a radially inwardly extending boss 86 defined at the distal extent of the medial haptic section about where the distal end foot portion of the haptic begins. This boss 86 defines an aperture 88. Figure 16 illustrates that the lens 10 of Figures 15 and 16 may be placed in its constrained-haptic condition by forming a loop 30 of suture material through the apertures 88 and connecting the bosses 86. This suture material loop is similar to the feature seen in Figure 2, except that the lens 10 of Figures 15 and 16 includes the bores 74 for additionally receiving the distal end portions 22 of the haptics 14. Consequently, as the loop 30 is drawn tight, the distal end portions 22 are inserted into the bores 74, and the lens 10 in its constrained-haptic condition is without free or exposed haptic ends which might catch on eye tissues at the surgical incision. While the present invention has been depicted, described, and is defined by reference to particularly preferred embodiments of the invention, such reference does not imply a limitation on the invention, and no such limitation is to be inferred. The invention is capable of considerable modification, alteration, and equivalents in form and function, as will occur to those ordinarily skilled in the pertinent arts. The depicted and described preferred embodiments of the invention are exemplary only, and are not exhaustive of the scope of the invention. Consequently, the invention is intended to be limited only by the spirit and scope of the appended claims, giving full cognizance to equivalents in all respects.

Claims: CLAIMS 1. An intraocular lens comprising: an optic body having an outer diameter, said optic body defining an effective optical diameter which is substantially the same as said outer diameter; an elongate support haptic extending outwardly and circumferentially on said optic body to define a distal end foot portion whereat said haptic is supportingly engageable with surrounding eye tissue, said distal end foot portion terminating in a distal end for said haptic, in a first unconstrained position said haptic foot portion being spaced radially from said optic body; and one of said optic body and said haptic defining cooperating means for engaging one of said optic body and a second haptic to constrain said haptic distal end foot portion in a second position adjacent said optic body. 2. The invention of Claim 1 wherein said cooperating means for engaging includes said intraocular lens having a second support haptic disposed generally diametrically opposite to and like said first-recited support haptic, said first-recited and said second haptic each including a distal end foot portion which defines a respective aperture, said cooperating means further including a flexible tension element extending through said apertures of each of said irst-recited and said second haptics and drawing the latter into second positions in which said distal foot portions are adjacent said optic body. 3. The invention of Claim 1 wherein said cooperating means for engaging includes said intraocular lens including a second support haptic disposed generally diametrically opposite to and like said first-recited support haptic, said first recited and said second support haptics each including a distal end portion which defines a shepherd's crook portion extending radially inwardly toward said optic body, whereby said support haptics in said second position thereof at said distal end foot portions thereof cross said optic body to enterengage said shepherd's crook portions one with the other. 4. The invention of Claim 1 wherein said cooperating means for engaging includes said optic body defining a boss extending radially outwardly and circumferentially outside of said effective optical diameter, said boss defining a circumferential arcuate groove opening axially, and a wall portion bounding said groove radially outwardly, in said second position of said haptic said distal end foot portion thereof being received into said groove to engage said wall portion of said boss. 5. The invention of Claim 4 wherein said intraocular lens includes a second support haptic disposed generally diametrically opposite to and like said first-recited support haptic, said second support haptic including a transition portion adjacent said optic body and from which the remainder of said second support haptic extends, said transition portion of said second support haptic defining said boss and said groove with said radially outer wall portion. 6. The invention of Claim 1 wherein said cooperating means for engaging includes said support haptic distal end foot portion including a bulbular end portion defining said distal end, said intraocular lens further including a second support haptic disposed generally diametrically opposite to and like said first-recited support haptic, said second support haptic including a transition portion and a proximal curve section cooperating with a proximal portion of a medial section of said support haptic and also with an adjacent peripheral surface of said optic body to define a bite into which said distal end foot portion of said first-recited support haptic is receivable in said second position thereof, and said bulbular end portion being captively receivable adjacent to said bite. 7. The invention of Claim 1 wherein said cooperating means for engaging includes said support haptic distal end foot portion including a bulbular end portion defining said distal end, said distal foot portion further including a radially outwardly disposed recess and a radially outwardly extending projection distally of said recess and adjacent to said bulbular end portion; said intraocular lens further including a second support haptic disposed generally diametrically opposite to and like said first-recited support haptic, said second support haptic including a transition portion adjacent said optic body and leading to a proximal curve section having a reentrant curve portion; said transition portion, proximal curve section and reentrant curve portion cooperatively defining a cove into which said radially outwardly disposed recess of said first-recited haptic is receivable. 8. The invention of Claim 7 wherein said second haptic at a proximal portion of a medial section thereof adjacent to said cove defines a radially inwardly convex curve defining a radially inwardly extending projection, and said radially outwardly extending projection of said first-recited haptic engaging said radially inwardly extending projection in said second position of said first-recited haptic. 9. The invention of Claim 1 wherein said cooperating means for engaging includes said support haptic defining a distal end foot portion of substantially constant size and shape near said distal end thereof, and said optic body defines a blind bore matching said size of said haptic distal end foot portion and extending inwardly thereof tangentially to a diameter only sufficiently smaller than said diameter of said optic body that said bore includes a radially outer wall portion and transects a peripheral surface of said optic body to define a circumferential groove thereon, said distal end foot portion in said second position of said haptic being captively received in said bore. 10. The invention of Claim 9 wherein said distal end foot portion defines an interference fit within said blind bore. 11. The invention of Claim 9 wherein said intraocular lends further includes a second support haptic disposed generally diametrically opposite and like said first recited haptic, said first-recited and said second haptic each including a medial section defining a radially inwardly extending boss projecting toward said optic body, each of said bosses defining a respective aperture, and a flexible tension member engaging said bosses and drawing said first-recited haptic to said second position thereof. 12. An intraocular lens comprising: an optic body; a pair of like elongate support haptics generally disposed on opposite sides of said optic body and each extending radially outwardly and circumferentially to define a respective distal end foot portion supportingly engageable with eye tissue and terminating in a respective distal end spaced from said optic body in a first position of said pair of haptics; said pair of haptics defining cooperating constraining means for engaging one another to each constrain the other in a second position wherein said distal end of each is adjacent to said optic body. 13. The intraocular lens of Claim 12 wherein said cooperating constraining means includes said pair of haptics each defining a respective aperture in said distal end foot portion thereof, and an elongate flexible tension member engaging each of said pair of haptics at said respective aperture and drawing said haptics toward one another to said second position thereof. 14. The invention of Claim 13 wherein said elongate flexible tension member includes a loop of suture thread extending through said apertures of said pair of haptics. 15. The invention of Claim 12 wherein said cooperating constraining means includes each of said haptics at said distal end foot portion thereof defining a shepherd's crook portion, said shepherd's crook portion of said haptics being releasably enterengageable with one another to constrain said pair of haptics in said second position thereof. 16. The invention of Claim 15 wherein said shepherd's crook portions of said haptic distal end foot portions extend radially inwardly toward said optic body. 17. The invention of Claim 12 wherein said cooperating constraining means includes each of said pair of haptic distal end portions defining a respective one of a pair of bulbular end portions which respectively define said distal ends of said haptics, and each of said haptics cooperating with said optic body to define a respective one of a pair of bites, each one of said pair of bites respectively capturing the bulbular end portion of the other haptic in said second position for said pair of haptics. 18. The invention of Claim 12 wherein said cooperating constraining means includes each of said pair of haptics at said distal end portions thereof defining a respective bulbular end portion which defines said distal end for said haptic and a radially outwardly extending projection proximal of said bulbular end portion and distal of a radially outwardly disposed recess, and each of said pair of haptics cooperating with said optic body to define a respective cove adjacent to the latter and a radially inwardly extending projection distal of and adjacent said cove; in said second position of said pair of haptics the recess of each haptic foot portion being received in said cove of the other with the radially outwardly extending projection of the respective foot portion releasably engaging the radially inwardly extending projection of the other haptic adjacent said cove. 19. An intraocular lens comprising: an optic body having an outer diameter; a pair of like elongate support haptics generally diametrically disposed on said optic body and each extending therefrom radially outwardly to a distal end foot portion supportingly engageable with eye tissue and terminating in a respective distal end which in a first position of said pair of haptics is spaced from said optic body, said distal end foot portions adjacent to said distal end being of a certain dimension in cross section; said optic body defining a pair of diametrically opposite peripheral bores substantially matching said haptic certain dimension and tangent to a circle of diameter just sufficiently smaller than said outer diameter so that each said bore includes a radially outer bore portion and transects a peripheral surface of said optic body to define a groove therein, in a second position of said pair of haptics said distal end foot portion of each adjacent to said distal end thereof being captively received into a respective one of said pair of peripheral bores. 20. The intraocular lens of Claim 19 wherein said distal end foot portions of said pair of haptics each define an interference fit in said peripheral bores. 21. The intraocular lens of Claim 19 wherein each of said pair of haptics further includes an aperture intermediate said distal end thereof and said optic body, and a length of flexible elongate tensile member engaging said haptics at said apertures and drawing said haptics to said second position thereof. 22. The invention of Claim 21 wherein each of said pair of haptics defines a radially inwardly extending boss thereon, said boss defining said aperture for each one of said of pair of haptics. 23. An intraocular lens comprising: an optic body; a pair of like elongate support haptics generally disposed on diametrically opposite sides of said optic body and each extending radially outwardly and circumferentially to define a distal end foot portion which is supportingly engageable with eye tissue and terminating in a distal end spaced from said optic body in a first position of said haptics; said lens defining a pair of circumferentially extending grooves open axially and each having a respective radially outer wall portion bounding a respective one of said pair of grooves; in a second position of said pair of haptics the latter being elastically distorted to dispose said distal ends thereof adjacent to said optic body and a portion of each one of said pair of haptics being releasably received in one of said pair of grooves against said outer wall portion. 24. The intraocular lens of Claim 23 wherein said optic body carries a pair of radially outwardly and circumferentially extending bosses each defining a respective one of said pair of grooves. 25. The intraocular lens of Claim 23 wherein said pair of haptics each includes a transition portion adjacent said optic body and from which a remainder of each haptic extends, said transition portions each defining a respective one of said pair of grooves.

Inventors: RHEINISH ROBERT SCOTT, RICHARDS THOMAS P, TONKS ALLAN R, RHEINISH, ROBERT, SCOTT, RICHARDS, THOMAS, P., TONKS, ALLAN, R.
Applicants: KABI PHARMACIA OPHTHALMICS INC, KABI PHARMACIA OPHTHALMICS, INC.
Application year: 1994
Main classification: A61F2
IPC codes: A61F2